Numerous systems have been proposed for controlling the flow of air to a low air loss inflatable air mattress. For example, Suzuki et al., in U.S. Pat. No. 6,108,843 employed a set of on/off valves in combination with pressure sensors to control pressures within a set of air sacks of an air mattress. Schild, in U.S. Pat. No. 5,117,518 discloses a rotating valve to alternately supply air to sets of air chambers in an air mattress. Thomas et al, in U.S. Pat. No. 5,095,568 teach a flat plate valve system for distributing air to an air mattress.
The prior art evidences a search for a simple, reliable and compact means for providing a flow of air to the chambers of a low air loss air mattress. Numerous complex valves for controlling the flow of air have been developed.
One object of the present invention is to provide a simple, compact air mattress air supply and control system that is able to operate in different modes to supply air to different types of air mattresses.
Another object of the present invention is to provide an air mattress air supply and control system having a fan and motor that will not over heat as is now the case with many existing systems.
Yet another object of the present invention is to provide an air mattress air supply and control system that can receive an input corresponding to the weight of the supported patient, sense pressure in the chambers of various zones of the mattress, convert those sensed pressures to interface pressures between the patient and the mattress depending on the location of the zone and weight of the patent and then control the flow of air to an air mattress so that the patient/mattress interface pressure in each zone remains below a selected value to prevent the formation of bed sores.
Still yet another object of the present invention is to provide an air mattress air supply and control system that can be quickly deflated with reverse air flow so that cardiopulmonary resuscitation can be administered to a patient supported by the mattress.